No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinence of any cited documents.
Optical fiber transmission systems are employed in data centers to optically connect one optical device (e.g., a router, a server, a switch, etc.) with another set of optical devices.
Current data centers are configured with multimode optical fibers coupled to 850 nm multimode VCSELs (Vertical Cavity Surface Emitting Lasers) light sources that provide modulated data signals to the multimode fibers. Such multimode fibers are used because the light sources in the transceivers in the optical devices are multimode light sources. Also, historically it has been easier to work with multimode fiber than single-mode fiber. Unfortunately, multimode fiber has a smaller bandwidth-distance product due to mode dispersion, which makes it difficult and expensive to extend the reach of the optical fiber transmission system while maintaining high-bandwidth transmission. Furthermore, utilizing a typical transmitter (that utilizes a 850 nm VCSEL) operating at 10 Gb/s as a source, current standard OM3 and OM4 multimode optical fibers can transmit optical signal over a distance of only about 300 m to about 500 m, due to signal distortion caused by the chromatic dispersion introduced by silica material of these multimode fibers. As optical transmission speed moves to 25 Gb/s or higher, this distance becomes even shorter (75 m to 150 m) due to chromatic dispersion for the current standard OM3 and OM4 multimode optical fibers operating at around 850 nm. Consequently, other ways of increasing the transmission distance of the optical fiber transmission system without incurring the time, labor and expense having to replace the existing multimode optical fiber are needed.